1. Field of the Invention
The present invention relates generally to a rip fence for a sawing machine such as a table saw, and more specifically to a rip fence mechanism for a sawing machine, which can stably support the workpiece under cutting.
2. Description of the Related Art
A conventional table saw is generally equipped with a rip fence for stopping at a lateral side of a workpiece under cutting so as to determine and restrict the cutting width of the workpiece. By means of the cooperation of rails with channels, the rip fence is slidably moveable relative to the worktable; further, the rip fence can be locked in any position by using a locking device clamping on a lateral side of the worktable or on the rail. If a to-be-cut workpiece has a width greater than that of an effective support zone of the worktable, the rip fence will need to be pulled outwardly away from the worktable to a proper distance for enabling the rip fence to be stoppable at the lateral side of the workpiece so as to determine the cutting width of the workpiece. Under this condition, a part of the workpiece will be suspended outside the worktable, such that the workpiece may not be firmly supported in the cutting process.
Another conventional table saw having a fixed primary worktable and an auxiliary table moveably connected with the primary worktable is now commercially available. In this design, the rip fence is constructed to be moveable along and positionable on the primary worktable or the auxiliary table. When a small-sized workpiece is to be cut, the rip fence can move along a direction toward or away from the saw blade to a desired position where the rip fence can properly stop at the lateral side of the workpiece, such that the cutting width of the workpiece can be determined. On the other hand, when a large-sized workpiece is to be cut, the auxiliary table will need to be pulled away from the primary worktable to a desired distance for extending the effective support width of the table saw and for enabling the rip fence that is set on the auxiliary table to be stoppable at the lateral side of the workpiece. This design can offer a better support effect to a large-sized workpiece during cutting. However, the structures and relationships among the primary worktable, the auxiliary table and the rip fence are much more complicated in design.